LE3 Abdomen 2024 Flashcards

Question

27. The radiographic sign suspicious for sigmoid volvulus is: A. Northern exposure sign B. Frimann-Dahl sign C. Liver overlap sign D. Coffee bean sign

Answer 1

D. Coffee bean sign The coffee bean sign is a radiographic feature that is highly suspicious for sigmoid volvulus. It represents the appearance of the twisted loop of sigmoid colon, which takes on the shape of a coffee bean due to the distention of bowel loops filled with gas. Sigmoid volvulus is a condition where the sigmoid colon twists around its mesentery, leading to obstruction and potential bowel ischemia.

Answer 2

D. Pseudocyst The encapsulated collection of fluid and debris seen on CT scan in a patient with a history of severe pancreatitis is most likely a pancreatic pseudocyst. Pseudocysts are common complications of acute pancreatitis and contain pancreatic enzymes, necrotic tissue, and fluid. They are not true cysts as they lack an epithelial lining. Management depends on the size and symptoms, with some requiring drainage.

Answer 3

C. Volvulus A volvulus is an example of a closed-loop obstruction, occurring when a segment of bowel twists on itself and its mesentery, leading to a segment of bowel that is obstructed at two points. This creates a closed-loop obstruction, which is a surgical emergency due to the risk of strangulation and bowel necrosis. Symptoms include sudden, severe abdominal pain, vomiting, and signs of bowel obstruction.

Answer 4

C. Superior mesenteric artery The arterial supply of the small bowel is primarily provided by the superior mesenteric artery (SMA). The SMA arises from the abdominal aorta and supplies the entire small intestine, except for parts of the duodenum, and also provides blood flow to the ascending colon and part of the transverse colon. The celiac artery supplies the stomach, liver, and spleen, while the inferior mesenteric artery supplies the distal colon and rectum. The vasa recta are smaller vessels branching from the SMA to supply the intestines.

Answer 5

D. Valvulae conniventes Rationale: The valvulae conniventes, also known as plicae circulares, are folds in the mucosa of the small intestine that are continuous across the lumen, distinguishing the small bowel from the large bowel. In contrast, the large bowel has haustra, taenia coli, and lacks continuous folds like the valvulae conniventes.

Answer 6

C. Sigmoid colon Rationale: The sigmoid colon is the most common site for colorectal carcinoma, often presenting with symptoms like chronic constipation, altered bowel habits, and, in this case, the classic “apple-core” deformity on barium enema, indicative of a stenosing lesion caused by the tumor.

Answer 7

A. Diffuse increase in parenchymal echogenicity Rationale: An ultrasound finding of diffuse increased echogenicity of the renal parenchyma is indicative of renal parenchymal disease. This sign reflects chronic changes, such as scarring or fibrosis, within the kidney tissue, differentiating it from findings like dilatation of the renal pelvocalyces (seen in obstruction) or cavity formation (suggestive of abscess or advanced infection).

Answer 8

**Answer: A. Gut obstruction** The provided X-ray image demonstrates findings consistent with **gut obstruction**. The hallmark features seen in bowel obstruction on an abdominal X-ray include: - **Dilated bowel loops**: The small intestine is visibly dilated, with air-fluid levels present, suggesting an obstructive process. The presence of multiple air-fluid levels is particularly characteristic of a small bowel obstruction. - **Step-ladder appearance**: This appearance is due to the dilated loops of bowel stacked on top of each other. The presence of dilated loops with air-fluid levels, as seen in the upright abdominal X-ray, indicates a **mechanical obstruction** of the bowel. Depending on the location and nature of the obstruction, the clinical management can involve conservative treatment, such as nasogastric decompression, or surgical intervention if there is a risk of strangulation or bowel perforation. It is essential to evaluate the patient clinically and correlate imaging findings with symptoms for appropriate management.

Answer 9

B. Ultrasound The modality of choice to evaluate a teenager with acute scrotal pain is ultrasound, specifically Doppler ultrasound. This imaging modality is non-invasive, readily available, and provides information about blood flow, which is crucial for diagnosing conditions such as testicular torsion (which requires prompt intervention), epididymitis, or testicular trauma. Doppler ultrasonography can assess perfusion and help differentiate between these conditions.

Answer 10

C. Perinephric fluid collection Forniceal rupture caused by high-grade obstruction coupled with high urine output will present on CT scan as a perinephric fluid collection. Forniceal rupture occurs when the increased pressure in the renal collecting system exceeds the threshold, causing a tear in the fornix of the renal calyx. This condition often results from an obstructive process, such as a kidney stone, that causes backpressure.

Answer 11

B. Klatskin tumor Abrupt termination of the extrahepatic common bile duct with upstream dilatation of intrahepatic ducts and an associated mass at the porta hepatis is suggestive of a Klatskin tumor. Also known as perihilar cholangiocarcinoma, Klatskin tumors are located at the bifurcation of the right and left hepatic bile ducts and cause obstructive jaundice. Imaging findings typically include ductal dilatation with a mass near the hepatic hilum.

Answer 12

C. Gut obstruction The small bowel feces sign is a localizing sign for gut obstruction. It appears as particulate material resembling feces within a dilated segment of small bowel on CT imaging. This finding results from prolonged stasis, leading to mixing of gas, fluid, and particulate matter, and is usually indicative of a chronic or subacute obstruction.

Answer 13

B. Lymphoma The presence of extensive retroperitoneal lymphadenopathy with a homogeneous, round, poorly-enhancing renal mass is most likely due to lymphoma. The kidney is a common extranodal site of involvement for Non-Hodgkin lymphoma, which may present with poorly enhancing renal masses or retroperitoneal lymph nodes invading the kidneys. Primary renal lymphoma is rare, and involvement of the kidney often occurs as part of disseminated disease.

Answer 14

D. Target sign The typical sign of intussusception seen on ultrasonography is the target sign. Intussusception occurs when one segment of bowel telescopes into another, leading to bowel obstruction and potentially ischemia. On ultrasound, it appears as concentric rings, giving a "target" or "doughnut" appearance in the transverse view. The gold standard for diagnosis and treatment is a contrast enema, which can also reduce the intussusception. The coiled spring sign may be seen on contrast studies, representing the intussusceptum prolapsing into the lumen.

Answer 15

D. Appendiceal dilatation of more than 6 mm in diameter CT and ultrasound findings suspicious for acute appendicitis include an appendiceal diameter greater than 6 mm, wall thickening greater than 2 mm, adjacent mesenteric fat stranding, and possibly the presence of appendicolith. Other findings may include loss of the clear periappendiceal fat planes and avascularity on Doppler due to inflammation or necrosis. Ultrasound can be particularly useful in pediatric and pregnant patients to confirm the diagnosis.

Answer 16

D. Sharply defined far wall The ultrasound criteria for a simple renal cyst include a sharply defined far wall, anechoic content (no internal echoes), and posterior acoustic enhancement. A simple renal cyst is benign, and its appearance on imaging should be homogenous with no septations, calcifications, or solid components.

Answer 17

C. Left lateral decubitus (left side down) To evaluate for pneumoperitoneum in patients who cannot tolerate upright films, the left lateral decubitus position is useful. In this position, any free air will rise and be visible on the right side of the abdominal cavity, especially between the liver and abdominal wall. The left lateral decubitus film is helpful to detect even small amounts of free intraperitoneal air, providing an alternative to the upright radiograph.

Answer 18

C. 4 Bosniak Category 4 cysts are necrotic cystic neoplasms or tumors that arise within a cyst wall and have a high likelihood of being malignant. These cysts have enhancing soft tissue components or thick, irregular walls and septa. Management typically involves surgical intervention due to the risk of malignancy.

Answer 19

C. Ultrasound of the abdomen The initial imaging test for a patient with right upper quadrant pain and a positive Murphy's sign is ultrasound of the abdomen. Acute cholecystitis is suggested by the clinical findings, and ultrasound is the preferred imaging modality for evaluating gallbladder pathology. Findings may include gallstones, thickening of the gallbladder wall, pericholecystic fluid, and a positive sonographic Murphy's sign.

Answer 20

C. Medullary sponge kidney Medullary sponge kidney is diagnosed by the presence of dysplastic dilatation of the collecting tubules in the renal papilla. This condition is characterized by cystic dilatation of the collecting ducts, which can lead to urinary stasis, stone formation, and sometimes recurrent urinary tract infections. Most patients are asymptomatic, and the kidneys often appear normal in size.

Answer 21

A. Adhesions The most common cause of small bowel obstruction (SBO) in adults is adhesions, which are fibrous bands that form after previous abdominal surgeries, causing loops of bowel to adhere to each other or to the peritoneal wall. Adhesions can create kinks or twists, leading to obstruction. Other causes include hernias, neoplasms, or volvulus, but adhesions remain the predominant etiology, especially in patients with a surgical history.

Answer 22

B. Contrast-enhanced CT scan The best imaging modality for suspected renal masses and tumors is a contrast-enhanced CT scan. CT provides detailed images of the renal parenchyma and can differentiate between benign and malignant lesions based on enhancement patterns. Contrast material helps highlight vascular structures and detect any abnormalities within the kidney.

Answer 23

D. The upper pole ureter is subject to vesicoureteral reflux In ureteral duplication, the Weigert-Meyer rule states that the upper pole ureter usually ends in an ectopic location and is prone to vesicoureteral reflux, while the lower pole ureter tends to drain normally but may be associated with ureterocele. In complete ureteral duplication, the upper moiety ureter is more likely to insert ectopically and have an abnormal course, leading to functional impairment and a risk of reflux.

Answer 24

B. Echogenic shadowing foci on ultrasound Cholelithiasis, or gallstones, typically appears as echogenic shadowing foci on ultrasound. The stones produce acoustic shadowing because they are dense structures that block the passage of ultrasound waves, creating a characteristic shadow behind the stone. Ultrasound is the preferred imaging modality for diagnosing cholelithiasis, as it is non-invasive and highly sensitive for detecting gallstones.

Answer 25

C. Lack of enhancement of the bowel wall The most specific sign of strangulated bowel on a contrast CT scan is the lack of enhancement of the bowel wall. Strangulation occurs when the blood supply to a segment of the bowel is compromised, leading to ischemia and necrosis. On CT imaging, a non-enhancing bowel wall indicates that there is no blood flow, suggesting ischemia. Other findings like circumferential wall thickening and edema can be seen in both strangulated and non-strangulated bowel obstructions, but lack of enhancement is more specific for ischemia.

Answer 26

C. Renal tuberculosis **Renal tuberculosis** is characterized by **renal parenchymal destruction**, **cavity formation**, **scarring**, and **strictures**. It occurs as a result of hematogenous spread from a primary pulmonary tuberculosis infection. The disease often leads to granulomatous masses, fibrosis, and strictures within the collecting system, resulting in cavitation, calcification, and eventual scarring of the renal parenchyma. These changes can lead to obstruction of the urinary tract and progressive renal damage. The findings of **parenchymal destruction**, **granuloma formation**, and **calcifications** are hallmarks of **renal tuberculosis**. This condition is diagnosed based on imaging studies and confirmed by microbiological testing, such as urine cultures for Mycobacterium tuberculosis.

Answer 27

A. Chronic pyelonephritis with reflux nephropathy Intrarenal reflux leading to damage to the renal papilla, calyceal blunting, and cortical scarring is seen in chronic pyelonephritis with reflux nephropathy. Reflux nephropathy is caused by VUR, in which urine flows back into the kidney, causing infections and chronic damage to the renal parenchyma. The scarring typically affects the upper and lower poles of the kidney and is associated with recurrent urinary tract infections.

Answer 28

B. Venous invasion is critical for surgical planning Evaluating the renal vein in cases of renal cell carcinoma (RCC) is crucial because venous invasion affects surgical planning. RCC is known for its propensity to invade the renal vein and even extend into the inferior vena cava. The presence of venous involvement can influence the surgical approach, as more extensive resection may be required to remove the entire tumor and any thrombus within the veins.

Answer 29

B. The double bubble sign may be seen on plain abdominal radiograph Malrotation with midgut volvulus can present with the double bubble sign on plain abdominal radiographs. This sign indicates two air-filled structures—the stomach and the proximal duodenum—suggesting an obstruction. Malrotation is a congenital anomaly where the intestines do not rotate properly during fetal development, leading to an abnormal position of the bowel and an increased risk of volvulus, which is a surgical emergency.

Answer 30

B. Calculi Calculi are the most common filling defect in the urinary tract on urography. Ureteral calculi (stones) appear as defects in the contrast column during intravenous urography. Other causes of filling defects include blood clots, transitional cell carcinoma, or tuberculosis, but calculi are by far the most common cause of obstruction and filling defects seen in the ureters.

Answer 31

C. "Target-like" enhancement Hepatic metastasis often shows a "target-like" enhancement pattern on CT imaging. This pattern is characterized by a central area of hypoattenuation surrounded by a rim of peripheral enhancement. The target-like appearance is indicative of the characteristic growth pattern of metastatic tumors, especially on contrast-enhanced scans.

Answer 32

B. Hepatic cyst The most common associated abnormality in autosomal dominant polycystic kidney disease (ADPKD) is a hepatic cyst. Hepatic cysts occur in over half of patients with ADPKD and are usually asymptomatic. Aortic dissection can also occur in ADPKD patients due to associated vascular abnormalities, but hepatic cysts are more common.

Answer 33

A. Ultrasound The recommended initial screening imaging for hydronephrosis is ultrasound. Ultrasound is non-invasive, inexpensive, and effective at detecting dilation of the renal pelvis and calyces, which is characteristic of hydronephrosis. Ultrasound can also help identify the cause of obstruction, such as a ureteral stone, and assess renal parenchymal thickness.

Answer 34

B. Intestinal wall Pneumatosis refers to the presence of air within the intestinal wall. Pneumatosis intestinalis can be associated with several conditions, including bowel ischemia, necrotizing enterocolitis, or trauma. The presence of air in the bowel wall is a concerning finding and may indicate a compromised bowel that requires urgent medical or surgical intervention.

Answer 35

B. Portal venous gas is peripheral in location Portal venous gas is typically peripheral in location, seen in the branches of the portal vein that extend to the periphery of the liver. It is an ominous sign often associated with small bowel infarction. Pneumobilia, on the other hand, is the presence of air in the biliary tree and is commonly visualized in the anterior portion of the liver. Pneumobilia may be seen after procedures like endoscopic retrograde cholangiopancreatography (ERCP) or in cases of biliary-enteric fistula, and it is not typically associated with bowel ischemia.

Answer 36

B. Calcification of the wall A characteristic finding of schistosomiasis of the urinary bladder is calcification of the wall. Schistosomiasis is a parasitic infection that leads to chronic inflammation and fibrosis, resulting in the calcification of the bladder wall. This can be seen on imaging as a "cobblestone" appearance, which is due to the calcified eggs embedded in the bladder wall.

Answer 37

D. Tendency to be multicentric In transitional cell carcinoma (TCC), careful evaluation of the entire urinary tract is warranted because of its tendency to be multicentric. TCC can occur simultaneously in multiple areas of the urinary tract, including the renal pelvis, ureters, and bladder, which makes complete imaging of the urinary tract important for accurate diagnosis and treatment planning. TCC is also linked to risk factors such as smoking and exposure to certain chemicals.

Answer 38

A. 6 hours The golden period for achieving 80% salvage of a testicle suspected of torsion is within 6 hours of the onset of symptoms. Testicular torsion is a urological emergency, and early diagnosis and intervention are critical to preserving testicular function. Surgical detorsion and fixation (orchiopexy) are performed to prevent recurrence.

Answer 39

D. Main portal vein The primary blood supply of the liver is the main portal vein, which provides about 75% of the liver's blood supply. The portal vein delivers nutrient-rich blood from the gastrointestinal tract, pancreas, spleen, and gallbladder to the liver for processing. The remaining 25% of the liver's blood supply is provided by the hepatic artery, which supplies oxygenated blood.

Answer 40

C. Nephrogram phase The nephrogram phase of a contrast-enhanced CT scan shows uniform enhancement of the renal parenchyma. This phase typically occurs about 90 to 120 seconds after the injection of contrast and provides optimal imaging of the renal cortex and medulla, which is useful for evaluating renal masses, scarring, and other abnormalities.

Answer 41

A. Bile ducts Pneumobilia is defined as the presence of air in the bile ducts. It can occur due to procedures such as ERCP, biliary-enteric anastomosis, or in the setting of infection with gas-forming bacteria. On imaging, pneumobilia can be distinguished from portal venous gas by its central location within the biliary tree and its branching pattern that extends toward the liver hilum.

Answer 42

C. Early arterial enhancement and subsequent rapid washout In a triple-phase CT scan of hepatocellular carcinoma (HCC), the classic finding is early arterial enhancement followed by rapid washout in the portal venous or delayed phase. This enhancement pattern is characteristic of HCC due to its arterial blood supply and helps differentiate HCC from other hepatic lesions.

Answer 43

C. Enhancing lesion in a background of low-attenuation urine Transitional cell carcinoma (TCC) of the urinary bladder typically presents on CT as an enhancing lesion within a low-attenuation urine background. TCC appears as a focal mass or area of wall thickening that enhances with contrast. The lesion may protrude into the bladder lumen or cause irregularity of the bladder wall.

Answer 44

C. Early arterial enhancement and subsequent rapid washout In a triple-phase CT scan of hepatocellular carcinoma (HCC), the classic finding is early arterial enhancement followed by rapid washout in the portal venous or delayed phase. This enhancement pattern is characteristic of HCC due to its arterial blood supply and helps differentiate HCC from other hepatic lesions.

Answer 45

C. 3 cm The small bowel is considered dilated when its diameter exceeds 3 cm on imaging. Small bowel dilatation can be a sign of obstruction, where the bowel proximal to the obstruction dilates due to the accumulation of gas and fluid. This is a common finding in small bowel obstruction, which can result from adhesions, hernias, or tumors.

Answer 46

B. Rat-tail deformity of the distal esophagus The characteristic radiographic feature of achalasia on a barium study is the rat-tail deformity or bird-beak appearance of the distal esophagus. Achalasia is a motility disorder characterized by failure of the lower esophageal sphincter (LES) to relax, leading to dilation of the proximal esophagus and tapering at the gastroesophageal junction, resembling a bird's beak or rat tail.

Answer 47

D. Wedge-shaped low-attenuation density extending to the renal capsule Acute pyelonephritis on a contrast-enhanced CT scan typically presents with wedge-shaped low-attenuation areas extending to the renal capsule. These areas represent regions of inflammation and edema in the renal parenchyma. Other findings may include perinephric stranding, renal enlargement, and areas of decreased perfusion.

Answer 48

C. Focal ileus adjacent to inflammation A sentinel loop is defined as a focal ileus that occurs adjacent to an area of inflammation. This finding is commonly seen in conditions such as acute pancreatitis, where a localized segment of bowel becomes dilated and lacks peristalsis due to nearby inflammation. It serves as a radiographic clue pointing to the underlying disease process.

Answer 49

A. Ascites Obliteration of flank stripes may be seen in ascites, which refers to the accumulation of fluid within the peritoneal cavity. Ascites causes increased density in the abdomen and displaces gas-filled bowel loops away from the flank, resulting in the loss of the normal flank stripe on radiographs. Ascites can be caused by a variety of conditions, including cirrhosis, congestive heart failure, or hypoproteinemia. Imaging findings include increased abdominal density, indistinct margins of the liver, spleen, and psoas muscles, and the displacement of gas-filled bowel. The presence of ascites can be confirmed with ultrasound or CT, which are more sensitive than plain radiography for detecting small volumes of fluid.

Answer 50

C. Cecal volvulus Cecal volvulus is indicated by marked distention of a loop of the large bowel with its long axis extending from the right lower quadrant to the epigastrium or left upper quadrant, showing a kidney-shaped configuration. Cecal volvulus occurs when the cecum twists upon itself, leading to bowel obstruction. Classic findings include a "coffee bean" or "kidney-shaped" distended bowel with haustral markings directed toward the left upper quadrant.

Answer 51

C. Presence of fat density The CT finding diagnostic of angiomyolipoma of the kidney is the presence of fat density within the lesion. Angiomyolipomas are benign renal tumors composed of blood vessels, smooth muscle, and fat. The presence of fat on CT is characteristic of these tumors and helps distinguish them from other renal masses.

Answer 52

A. Intussusceptum In intussusception, the prolapsing part of the bowel is called the intussusceptum, which telescopes into the distal segment of the bowel, known as the intussuscepiens. This condition is most common in children and can present with symptoms such as abdominal pain, vomiting, and the "currant jelly" stool. On imaging, the classic finding is the "target" or "doughnut" sign, representing the telescoped bowel loops.

Answer 53

B. Contrast-enhanced CT scan

Answer 54

A. Cavernous hemangioma

Answer 55

C. Ultrasound of the abdomen

Answer 56

B. Extension of the right lobe border below the kidney

Answer 57

C. Increased parenchymal echogenicity on ultrasound

Answer 58

C. Prominent central liver enhancement in early scan images

Answer 59

C. Ultrasound

Answer 60

A. Cavernous hemangioma

Answer 61

D. Hepatic cyst

Answer 62

A. Amoebic

Answer 63

A. Risk of hemorrhage

Answer 64

B. Innumerable regenerative nodules replacing normal hepatic parenchyma

Answer 65

D. Hepatitis B infection

Answer 66

C. Rapid washout during the portal venous phase

Answer 67

B. Commonly affects the posterior segment of the liver

Answer 68

B. Echogenic shadowing foci on ultrasound

Answer 69

D. Pancreatic head carcinoma

Answer 70

A. Cholangiocarcinoma

Answer 71

D. Pseudocyst

Answer 72

D. Vascular encasement

Answer 73

D. Scleroderma

Answer 74

B. Rat-tail deformity of the distal esophagus

Answer 75

C. Corkscrew appearance of the esophagus

Answer 76

C. H. pylori gastritis

Answer 77

A. Ulcerative colitis

Answer 78

A. Intussusceptum

Answer 79

D. Target sign

Answer 80

C. Ileocecal segment

Answer 81

C. Cecal volvulus

Answer 82

A. Gangrenous appendicitis

Answer 83

B. Mural hyperemia with color flow Doppler

Answer 84

A. Kirklin meniscus complex

Answer 85

B. Frimann-Dahl's sign

Answer 86

C. Pneumoperitoneum

Answer 87

A. Paraesophageal hernia

Answer 88

D. Annular constricting lesion

Answer 89

C. Ulcerative colitis

Answer 90

B. Diverticulitis

Answer 91

C. Cupola sign

Answer 92

D. Posterior cul-de-sac Rationale: The posterior cul-de-sac, also known as the rectouterine pouch (in females, Pouch of Douglas) or the rectovesical pouch (in males), is the most dependent portion of the peritoneal cavity when a person is in a supine position. Due to gravity, it tends to collect: • Ascitic fluid • Hemoperitoneum (blood) • Intraperitoneal metastases • Abscesses This is because it is the lowest point in the abdominal cavity when lying down, making it a common site for pathological fluid accumulation.

Answer 93

D. Winslow

Answer 94

D. Posterior cul-de-sac Rationale: The posterior cul-de-sac, also known as the rectouterine pouch (in females, Pouch of Douglas) or the rectovesical pouch (in males), is the most dependent portion of the peritoneal cavity when a person is in a supine position. Due to gravity, it tends to collect: • Ascitic fluid • Hemoperitoneum (blood) • Intraperitoneal metastases • Abscesses This is because it is the lowest point in the abdominal cavity when lying down, making it a common site for pathological fluid accumulation.

Answer 95

A. Centralization/medial displacement of bowel loops

Answer 96

B. Mucinous adenocarcinoma of the colon

Answer 97

A. Bowel perforation

Answer 98

B. 3 to 4 days

Answer 99

A. Football sign

Answer 100

D. Upright

Answer 101

B. Liver and diaphragm

Answer 102

D. Increased risk of gallbladder carcinoma

Answer 103

C. 2.5 to 3.0 cm

Answer 104

C. Sentinel loop

Answer 105

A. Acute appendicitis

Answer 106

B. Rapid infection with air densities dissecting the perineum

Answer 107

B. Blood adjacent to the injured organ

Answer 108

A. Cecal volvulus

Answer 109

B. Peptic ulcer disease

Answer 110

A. Adynamic ileus

Answer 111

C. Acute pancreatitis

Answer 112

D. Porto-mesenteric venous system

Answer 113

C. Pneumobilia

Answer 114

B. Usually composed of struvite

Answer 115

A. Ureteropelvic and ureterovesical junctions

Answer 116

A. Gallstones are anterior in location

Answer 117

A. Echogenic foci with shadowing

Answer 118

A. Calcific densities within the calyces

Answer 119

B. Thick irregular septations

Answer 120

A. Extravasation of contrast on CT

Answer 121

A. Inferior vena cava (IVC)

Answer 122

B. (+) 10 HU

Answer 123

A. May be evaluated using Doppler imaging

Answer 124

C. Delayed phase Rationale: The delayed phase of a CT urogram is the most appropriate phase to evaluate the urinary bladder. During this phase, contrast has had sufficient time to excrete into the urinary system, providing optimal opacification of the bladder, ureters, and renal collecting systems. • This phase typically occurs 5-15 minutes after contrast administration. • It is particularly useful for detecting: • Bladder tumors • Diverticula • Filling defects • Ureteral abnormalities Why Not the Others? 1. A. Nephrogram phase: • This phase occurs shortly after contrast administration (20-70 seconds) and primarily enhances the renal parenchyma. It is used for evaluating renal masses, but it is not optimal for the bladder. 2. B. Pyogenic phase: • This is not a standard phase in CT imaging. Likely a typographical error or a misunderstanding of “pyelographic phase,” which would relate to urinary system imaging but is still part of the delayed phase. 3. D. All of the above: • Only the delayed phase is specifically suited for optimal evaluation of the bladder, not the nephrogram phase or others.

Answer 125

D. Transitional cell carcinoma

Answer 126

B. Diffuse wall thickening

Answer 127

B. Gas-producing bacteria

Answer 128

B. < (+) 10

Answer 129

A. Metastatic disease